Fixing means for elements of prismatic contour



April 27, 1937. WIRTH 2,078,824

FIXING MEANS FOR ELEMENTS OF PRISMATIC CONTOUR Filed April 14, 1934 3 Shets-Sheet 1 [/7 149/7 50/3: Jrmin MP1??- Arrow/Er.

A. WIRTH 2 ,078,824

FIXING MEANS FOR ELEMENTS OF PRISMATIC CONTOUR April 27, 1937.

Filed April 14, 1954 3 Sheets-Sheet 2 ATTORNEY.

A. WIRTH April 27, 1937.

FIXING MEANS FOR ELEMENTS OF PRISMATIC CONTOUR 3 Sheets-Sheet 3 Filed April 14, 1934 Fly. 9

Patented Apr. 27, 1937 FIXING MEANS FOR ELEMENTS OF PRISMATIO CONTOUR Armin Wirth, Ebingen, Wurttemberg, Germany,

assignor to August Sauter, Pracisrons-Waagen- & Gewichte-Fabrik,

Ebingen, Wurttemberg,

Germany, a German firm Application April 14, 1934, Serial No. 720,666 In;Germany April 15, 1933 3 Claims.

This invention relates to the fixing elements of prismatic profiles, such as edge pieces for balances, in bores.

The known fastening means for the edges of 5: balances, which are usually triangular or pearshaped profiles, do not meet modern requirements as to economy and accuracy and the elimination of difficult hand work. Great difficulties have to be overcome already in producing the profile 10 hole, as broaches cannot be insertedand guided with the requisite degree of accuracy, and the tools and machines needed are quite expensive. In case of single jobs or small series this method, anyhow, cannot be applied, since'theproduction 15 of auxiliary devices and tools would not pay, and there is no choice left but to resort to hand work again. The rough drilled or roughened out holes are then'filed out by hand, mostly in a conical manner, .whereuponthe conical edge piece is innot insure good fitting, it is the general practice to caulk it, and it is left to the skill of the workman tosee to it that the edge piece is in proper position and held tight. When a singlejob is made, controlling devices are, as a rule, lacking, and the accuracy of the'work'is therefore often not very great.

If the edge member is not passed throughthe lever but secured openlywith one edge exposed, working conditions under the old processes are somewhat more favorable. on the machine; though this does often notpay in single jobs, but. it is hardly possible to cut so accurately that the edges will have the correct relative position without any finishing of the slots or edge member, so that the various parts have to be fitted again by hand.

According to existing methods of work, the edge member is usually conical in shape. Repeated deflections will loosen the seat of the edge member with the result that recaulking is required. When damaged edge members have to be exchanged, spare members cannot replace them without trouble, because, owing to manual work, irregularities will appear in the slots or on the edge member and interfere with close fitting. If the ends of the edge member strike also the joint cheeks, a new difiiculty arises, as the edge member to be inserted or replaced has to be driven in to exactly the same depth as before.

The invention eliminates the drawbacks enumerated by securing the triangular, square or polygonal profiles, e. g., edge members for balances, in bores or recesses by means of taper pins serted. As manual working. out of the hole does- The slots can be cut which serve for keying the profiled pieces in and to the bores and clearances.

By way of example, various embodiments of the invention are illustrated in the accompanying drawings by front views and ground plans.

Figures 1 and.2 are respectively an end elevation and atop plan view of an element of prismatic profile showing the adaptation therewith of a fixing means thereforin accordance with this invention,

Figures 3 and 4 are views corresponding respectively to Figures 1 and 2 of a modified form of fixing means,

Figures 5 and 6 are views corresponding respectively to Figures 1 and 2 illustrating another modified form of fixing means,

Figures '7 andS are views corresponding respectively to Figures land 2 illustrating still another modifiedform of fixingmeans,

Figures 9 and 10 are views corresponding respectively to Figures 1 and 2 illustrating still another modified form of fixing means, and

Figure 11 is a perspective view. of an element of square cross sectionand the adaptation therewith of a pair of fixing pins therefor.

With reference to Figures 1 and 2, a beam indicated at l is-formed with a main or primary bore 5 in which the prismatic element i. e., the edge member 4 of a balance is to be secured in correct position. The beam I is formed with auxiliary bores 2, the cross section of which covers partly that of the main bore 5. Extending through the auxiliary bores 2 are tapered pins Bprovide'dwith recesses or grooves 6' extending obliquely to their axes and taking the edges of the member 4. The bores 2 and 5, if necessary may be directed obliquely to the desired direction of member 4. The bores 2 open into the bore 5. Those bores 2 which receive the pins 6 are arranged in alignment.

The form of the invention shown in Figures 3 and 4 is substantially the same as that shown in Figures 1 and 2, with this exception that the prismatic member, indicated at 4 is of triangular cross section instead of square cross section as is member 4.

With reference to Figures 5 and 6, the profiled or edge member 4 is openly arranged in a clearance l on both sides of which auxiliary bores I are arranged which extend obliquely to the desired direction of the member i. The latter is of square cross section. The tapered pins are indicated at 6.

With reference to Figures '7 and 8 the profiled or edge member 4 is secured in a pair of endwise aligning main bores 5, into each of which open a plurality of auxiliary bores 2. The taper pins 6 in one of the aligned main bores are oppositely disposed with respect to the taper pins 6 mounted in the other bore 5. The auxiliary bores 2 opening in one of the main bores of said pair endwise align with the auxiliary bores 2 opening into the other main bore of the pair. With respect to the form shown by Figures 7 and 8 it is preferable to use a harder material for the taper pins than that employed for the beam l to avoid excessive stresses.

With reference to Figures 9 and 10 they disclose a pair of members 4 anchored to beam l.

The edge member G has a part of the length of a corner thereof flattened, as indicated at 4 to provide a clearance. The advantages in production, adjusting and repairing afforded by the new attachment are evident. In case of mass production the bores for the taper pins can be drilled by means of gages, and if single jobs are concerned, the bores will be adjusted on the dividing machine according to the calculated measurements by means of the dividing spindle and drilled. The bores serving for fastening are preferably in alinement to simplify production. When the bore for it has been finished, the profiled or edge member is inserted at once and can be longitudinally displaced exactly on the edge line to any desired degree by moving the taper pins in the beam I If an edge is worn down by use, the profiled or edge member is simply turned so as to replace the damaged edge by a new one. Previous marking of the taper pins will insure their being inserted in the beam I at exactly the same depth, so that the profiled or edge member will occupy again the correct position Without readjustment.

The conicity of the taper pins is very small and amounts to about 1:20 to 1:50, so that the pro- 40 filed or edge member can be safely displaced to the extent of fractions of one-tenth of a millimeter.

If the profiled or edge member is passed through the lever and a bearing is provided on both sides 45 thereof, it is advisable to provide a bore centrally to the member, in which a joint cheek is secured. This cheek is cut so that the edge member can be pushed in and the central recess thereof will be arranged during attachment in such a way that 50 the connection of the ends of the members is interrupted by the cheek against which the bearings, not shown, will abut.

The joint check is a cylindrical pin provided with spherical ends so as to have the latter supplement one another to form a ball cup. The connection of the ends of the edge will then always strike the highest point of this ball, no matter at what angle the bores or taper pins extend relative to the axis of the beam.

I claim:-

1. In a fixing means for a prismatic object, a prismatic object, an element having a primary opening for receiving the prismatic object free from the walls of said opening and spaced auxiliary cylindrical openings communicating at their inner sides with said primary opening and forming enlargements thereof, and fixing pins having wedge-shaped surfaces, each fixing pin having a lengthwise portion of its body extending through an auxiliary opening and the remaining lengthwise portion of its body extending through the primary opening, said pins being in wedging engagement with the walls of the auxiliary openings and with said object, the object being only in contact with such pins whereby the object is fixed stationary to said element exclusively by the wedging action of the pins.

2. In a fixing means for a prismatic object, a prismatic object, an element having a primary opening for receiving the prismatic object free from the walls of said opening and spaced auxiliary cylindrical openings having the same direction as, communicating at their inner sides with and forming enlargements of said primary opening, and fixing pins having wedge-shaped surfaces, each fixing pin having a lengthwise portion or" its body extending through an auxiliary opening and the remaining lengthwise portion of its body extending through the primary opening, said pins being in wedging engagement with the walls of the auxiliary openings and with said object, the object being only in contact with such pins whereby the object is fixed stationary to said element exclusively by the wedging action of the pins.

3. In a fixing means for a prismatic object, a prismatic object, an element having an opening for receiving the prismatic object free from the Walls of said opening, and fixing pins having wedge-shaped surfaces positioned in spaced location in opposite direction to each other in said opening and being in wedging engagement with the walls of the opening and with said object, the object being only in contact with such pins whereby the latter is fixed stationary to said element exclusively by the wedging action of the pins.

ARMIN WIRTI-I. 

